TY - BOOK

T1 - Studies on the corrosion mechanism of Zn-Al-Mg hot-dip galvanized steel sheets

AU - Keppert, Timothy

N1 - embargoed until 08-11-2018

PY - 2013

Y1 - 2013

N2 - In this work the corrosion behavior of Zn-Al-Mg hot-dip galvanized steel sheets was investigated with the goal to get some insight into the corrosion mechanism of said alloy. As reference material in all corrosion tests conventional hot-dip galvanized, Galfan and Galvalume material was used. To achieve this goal standardized corrosion tests as well as custom corrosion tests were used. The standardized tests performed were the standardized salt spray test, the VDA 621-415 test, the VDA 233-102 test, the condensation atmosphere with constant humidity test and the condensation climate with alternating humidity and air temperature test. Additionally salt spray tests with a variation of the pH value, the cation and the anion were performed. The corroded samples were visually inspected and analyzed. Cross section cuts were investigated by SEM and EDX to study the type and degree of the corrosive attack as well as to study the formation of the corrosion product layers. The composition of the corrosion products was analyzed with XRD, Raman and IR spectroscopy. In this way the formation kinetics as well as the composition of the corrosion products could be obtained. With all this information a corrosion mechanism for Zn-Al-Mg hot-dip galvanized steel sheets was formulated and tested for its plausibility and viability in every conceivable environment.

AB - In this work the corrosion behavior of Zn-Al-Mg hot-dip galvanized steel sheets was investigated with the goal to get some insight into the corrosion mechanism of said alloy. As reference material in all corrosion tests conventional hot-dip galvanized, Galfan and Galvalume material was used. To achieve this goal standardized corrosion tests as well as custom corrosion tests were used. The standardized tests performed were the standardized salt spray test, the VDA 621-415 test, the VDA 233-102 test, the condensation atmosphere with constant humidity test and the condensation climate with alternating humidity and air temperature test. Additionally salt spray tests with a variation of the pH value, the cation and the anion were performed. The corroded samples were visually inspected and analyzed. Cross section cuts were investigated by SEM and EDX to study the type and degree of the corrosive attack as well as to study the formation of the corrosion product layers. The composition of the corrosion products was analyzed with XRD, Raman and IR spectroscopy. In this way the formation kinetics as well as the composition of the corrosion products could be obtained. With all this information a corrosion mechanism for Zn-Al-Mg hot-dip galvanized steel sheets was formulated and tested for its plausibility and viability in every conceivable environment.

KW - Korrosion

KW - Schmelztauchverzinkung

KW - Zink

KW - Aluminium

KW - Magnesium

KW - corrosion

KW - hot-dip galvanizing

KW - zinc

KW - aluminum

KW - magnesium

M3 - Doctoral Thesis

ER -